WASHINGTON (CNN) --Ralph Nader will not seek the Green Party's nomination for president in 2004, but he's still considering a presidential candidacy as an independent, a Green Party official said Tuesday.

Ben Manski, Green Party co-chairman, said Nader called him Monday to give him the news.

"That was disappointing and unexpected and I was certain that the party membership would regret that he made the decision," Manski said.

In 2000, Nader won the Green nomination for president. Nader was on the ballot in 44 states and finished third with 2,878,000 votes (2.7 percent), according to the Green Party Web site.

Some Democrats blamed Nader, 69, for siphoning off votes that might have gone to Democratic candidate Al Gore, especially in the hard-fought state of Florida, where Nader took 97,000 votes.

"Gore beat Gore," Nader said earlier this month. "He didn't get Tennessee, his home state. That would have made him president. And he blundered in Florida and didn't ask for a statewide recount."

Manski said Nader gave no clear reasons for his decision.

"He's holding a lot very close to his chest," Manski said. Manski said he told Nader he thought it was a poor decision that would weaken both Nader and the Green Party's chances in the election if he were to run as an independent.

Nader did not return CNN's calls seeking comment on the report. A spokeswoman at his presidential exploratory committee referred calls for Nader to the Green Party.

I think there's a great need for a progressive candidate for the presidency," Nader said earlier this month. "The two parties are very much dialing for the same commercial dollars. The two parties are ignoring issues like a living wage."

In the 2000 race, Nader raised $8 million. He said if he mounts another campaign he hopes to raise between $5 million and $10 million.